Speed control mechanism



J1me 1942- J. M. LUCARELLE EI'AL 2,286,187

SPEED CONTROL MECHANISM Filed Jan. 18, 1941 INVENTORS Joseph M.Lucarelle BY Charles Ec/cland Patented June 16, 1942 SPEED CONTROLMECHANISM Joseph M. Lucarelle and Charles Ecklund, Bridgeport, Cnn.,assignors to Dictaphone Corporation, New York, N. Y., a corporation ofNew York Application January 18, 1941, Serial No. 374,998

6 Claims.

This invention relates to a speed control mechanism for commercialphonographs and more particularly to means for operating aspeedregulating device from a relatively remote point.

In commercialphonographs, because it is desirable that the record speedsuit the speech characteristics of the dictator and the ability of thetranscriber, it has been usual to provide commercial phonographs withspeed-control mechanisms, such, for example, as the governor-brake typeshown in U. S. Patent 1,625,093 to Renholdt. Such speed controlmechanisms have proved to be quite satisfactory. However, it isfrequently desirable and advantageous, especially in machines of thetranscribing type where a single machine is employed to reproducerecords recorded on several different dictating machines, to facilitatethe operation of speed adjustment by having the speed control knob in areadily accessible position so that the speed of reproduction may easilybe made to accord with the speed at which the record was made. In thepast this has been accomplished by carrying a rigid shaft from thespeed-regulating device to a control knob on the exterior of themachine, as shown, for example, in the above-mentioned patent. Such anarrangement has the disadvantage that it limits the number of positionsavailable for the control knob. Further, with such an arrangement, motorvibrations are transmitted to the control knob, and the efficiency ofthe customary resilient motor suspension is affected by the contact,even through damping material, of the control shaft with the phonographframe.

7 It is an object of this invention to provide a speed control mechanismavoiding these difficulties in which a speed-regulating device may beadjusted accurately and without hysteresis or backlash by means of acontrol lever remotely positioned with respect to the speed-regulatingdevice and connected thereto by a simple and relatively light flexibleconnection. Other objects will be in part obvious and in part pointedout hereinafter.

The invention, accordingly, consists in the features of construction,combination of elements, and arrangements of parts which will beexemplified in the structure to be hereinafter described and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawing, in which is shown one of the variouspossible embodiments of the invention;

Figure 1 is a side elevation of a speed control mechanism made inaccordance with the present invention, showing a portion of the baseplate and motor of a phonograph;

Figure 2 is a front elevation of the parts shown in Figure 1;

Figure 3 is a rear elevation of the control unit forming a portion ofthe mechanism shown in Figure 1, taken on line 3-'3 of Fi u e 1;

Figure 4 is an enlarged cross-section of this control unit, taken online 4-4 of Figure 3; and

Figure 5 is a bottom plan view of the speedregulating device forming aportion of the mechanism shown in Figure 1, taken on line'5-5 in Figure1.

As shown in the accompanying drawing, the motor Hi is mounted upon andforms part of a motor frame I2 which is preferably suspended by springmountings 14 from the base plate 16 of the phonograph. This springsuspension of the motor frame 12 allows it to have movement relative tothe base plate 16, so that the vibrations of the motor and partsconnected thereto will not be transmitted to the base plate l6 nor tothe sound recording and reproducing mechanism attached thereto.

For controlling the speed of the motor, the motor shaft I8 is providedwith a speed-regulating governor which, in the embodiment of theinvention herein disclosed, comprises a plurality of weights 20 mountedon bow-springs 22 connected at one end to a sliding collar 24 carrying abrake disc 26, as can best be seen by referring to Figure 2,. When theshaft is rotated, the weights 20 are thrown outwardly by centrifugalforce, and this causes the springs 22 to bow and draw the brake disc 26outwardly from the motor, the other ends of the bow springs 22 beinganchored to the shaft I8 by a collar, not shown. The extent of travelingmovement of the brake disc 26 to the right, as seen in Figure 2, iscontrolled by the centrifugal force developed in the weights 2|) andtherefore the speed of shaft .I8, assuming that the brake disc 26 isfree to move.

By opposing the traveling movement of the brake disc 26, the speed ofshaft l8 of the motor can be varied since the pressure of the brake discagainst the means opposing its movement produces sufficient friction toretard the rotation of the brake disc. The amount of traveling movementallowed to the brake disc 26, therefore, determines the speed at whichthe motor may operate, according to a predetermined plan.

For the purpose of opposing the traveling movement of the brake disc 26,there is usually provided a braking mechanism, which, in the form hereinshown, comprises a pair of friction pads 28, whose position relative thebrake disc 26 may be suitably controlled. In the embodiment shown,referring to Figures 1 and 5, the pads 28 are carried by a yoke 30having a pivotal connection 32 to a rotatable speed-regulating lever 34.This speed-regulating lever 34 is preferably fulcrumed on a stud 36 on asupporting plate 38 which is secured directly to the motor frame I2 bymeans of bolts 48 which are also used to secure the spring mountings [4to the motor frame, the plate 38 being perforated at 42 toallow thebolts 40 to pass therethrough. r

This speed-regulating lever 34 may, of course, be operated in anysuitable way. In the past, for example, it has been usual to operatethis lever by means of a cam secured to one end of a rotatable shaftpassing through an aperture in the base plate 18 of the phonograph andadapted to be rotated by a control knob mounted on its other end, in themanner shown in the above-mentioned patent. Such an arrangement isdisadvantageous because it greatly limits the number of places on thephonograph in which the control knob may be positioned. In addition, thevibrations of the motor are transmitted along such a control shaft tothe control knob, thus making it more difiicult for an operator to makea proper speed adjustment, and also making it necessary to surround theshaft where it passes through the aperture in the base plate withvibration-damping material to suitably journal the shaft and preventsuch vibrations from being transmitted to the base plate. Further,contact between the control shaft and the base plate tends to influenceand impair the efficiency of the vibration-damping effect of the springmountings M of the motor II].

In accordance with the present invention, these disadvantages areeliminated by the provision of a Bowden-wire element between thespeed-regulating lever 34 of the speed-governor mechanism mounted on thesupporting plate 38 attached to the motor I0, and a suitable speedcontrol knob 44 attached to a control unit, generally indicated at 46,which may be positioned at any convenient place on the phonograph.

The control unit 46 comprises a bracket 48 shaped substantially as shownin Figures 1 through 4, which is adapted to be secured in any desiredposition on the phonograph frame by any suitable means such as screws 58passing through bent tabs 52forming part of the bracket. A rotatablecontrol shaft 54 is suitably journaled on the bracket 48 as shown inFigure 4, and the control knob 44 is attached to one end of this shaft,as by means of a set screw 56. A spiral-shaped cam 58 is secured to theother end of shaft 54 by means of a lock nut 68. The control shaft 54 isheld in .any position to which it is adjusted by the friction betweenthe facing surfaces of cam 58 and bracket 48 produced by the force of aspring 55 compressed between the bracket 48 and a flange 51 secured tothe control shaft 54, as shown in Figure 4. A lever 62 is pivotallyattached to the bracket 48 by means of a stud 64, as shown in Figure 3.This lever 62 is provided with a projecting portion 66 which acts as acam-follower riding on the surface of cam 58. This projection 66 alsoserves, in conjunction with a projection 68 on the cam 58, as a stop tolimit the range of rotation of control knob 44, shaft 54, and cam 58 toslightly less than one revolution.

A Bowden-wireelement 18, having the usual outer member, sheath 69, andinner member, operating wire H, connects the control unit 46 with thespeed-governing mechanism on the motor [0. One end 12 of the sheath 69of the Bowden-wire element 18 is threaded into and thus adjustablyanchored to a tab 14 on the bracket 48 of control unit 46, as shown inFigures 2 and 3, and its other end 16 is similarly anchored to a tab 18projecting from the supporting plate 38 of the speed-governing mechanismon motor In. Lock nuts and 82 are adjustably threaded onto the ends 12and 16 of the sheath -69 to permit them to be locked in any desiredposition with respect to the tabs 14 and 18, respectively. The end 84 ofthe inside member or operating wire ll of the Bowden-wire element 18,which projects beyond the end 12 of the sheath 69 is provided with anexpanded terminal member 86, positioned in a slot in the free end 63 ofthe control lever 62 of the control unit 46, as is best shown in Figures2 and 3. The other end 88 of the inner wire H of the Bowden-rwireelement 18, which projects beyond the end 16 of the sheath 69, isprovided with an expanded terminal member 90, positioned in a slot inthe end 92 of the speed-regulating lever 34, on the opposite side of thefulcrum 36 from the friction pads 28, as is best shown in Figures 2 and.5. A coiled spring 94 connects the supporting plate 38 to the end 92 ofthe speed-regulating lever 34 to bias this lever in a counterclockwisedirection, referring to Figure 5, to tend to hold the friction pads 28away from the brake disc 26. This spring 94 likewise maintains a directpull on the inner wire ll of the Bowdenwire element 18, thus biasinglever 62 of the control unit 46 in a counterclockwise direction,referring to Figure 3, so as always to press the cam-follower projection66 against the surface of cam 58. The frictional effect between thesesurfaces due to the pull of spring 14 and the friction between thefacing surfaces of cam 58 and bracket 48 tend to hold the speed controllever 62 in its adjusted position at all times.

In operation, when the control knob 44 is turned to rotate shaft 54 in acounterclockwise direction, referring to Figure 3, the cam-followingprojection 66 rides up toward the high point of cam 58, thus rotatinglever 62 in a clockwise direction, and thereby exerting a direct pull onthe inner wire H of the Bowden-wire element 10. This pull on the innerwire H of the Bowden-wire element rotates the speed-regulating lever 34in a clockwise direction, referring to Figure 5, against the tension ofspring 94, and forces the friction pads 28 against the brake disc 26 ofthe speed-governor on the motor [0, thereby adjusting its speed in themanner above-described, from any suitable remote point on the phonographand without transmitting vibration from the motor to any other part ofthe machine.

Another advantage of a speed control mechanism embodying the presentinvention is that the limits of the speed control range can be simplyand easily changed by threading the ends 12 and I4 of the sheath 69 ofthe Bowden-wire element 18 in and out of the tabs 14 and 18,respectively, so as to vary the length of this sheath between thesetabs. As the length of the sheath between these tabs is increased, thiseffectively shortens the inner wire I I which forces the yoke 38 and thefriction pads 28 closer to the brake anism effective at a slower speedthan that at which it would be effective if the length of the sheath 69between the tabs 14 and 18 was decreased.

It will be seen that there is provided by this invention a constructionof an essentially practical nature in which the several objects of thisinvention are attained.

As many possible embodiments may be made of the above invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawing is to beinterpreted as illustrative only and not in a limiting sense.

We claim:

1. A speed-controlling device for phonographs comprising, incombination, phonograph driving means, a supporting plate secured tosaid driving means, a speed-regulating member movably attached to saidplate and operatively connected to said driving means, resilient meansbiasing said member toward a predetermined position relative to saidplate, a control unit bracket adapted to be remotely positioned relativeto said driving means, a speed control lever movably attached to saidbracket, a Bowden-wire element extending between said plate and saidbracket, the sheath of said Bowden-wire being anchored at one end tosaid plate and at the other end to said bracket, one end of the movableinner wire of said Bowden-wire' element being secured to said speedcontrol lever and the other end being secured to said speed-regulatingmember to pull against the force of said resilient means when said speedcontrol lever is moved in one direction, means for holding said latterlever in any desired position against the action of said resilient meansthereby to position said speed-regulating member in any desiredposition, and means associated with one end of the sheath of saidBowden-wire element for adjusting its position with respect to itsanchorage to vary the limits of the range of control of said speedcontrol mechanism.

2. A speed-controlling device for phonographs, comprising, incombination, a phonograph motor, a brake-type governor for said motor, asupporting plate secured to said motor, a speedregulating memberrotatably attached to said plate for adjusting said governor, a singlespring for rotating said member to bias it toward a predeterminedposition relative to said plate, a control unit bracket remotelypositioned on said phonograph relative to said motor, a lever pivotallyattached to said bracket, a cam rotatably mounted on said bracket formoving said lever to any desired position against the pull of saidspring, a control knob for positioning said lever, and a Bowden-wireelement extending between said plate and said bracket, the sheath ofsaid Bowden-wire being anchored at one end to said plate and at theother end to said bracket, one end of the movable inner wire of saidBowdenwire element being secured to said lever and the other end beingsecured to said speed-regulating member so as to pull against saidspring when said lever is rotated in one direction by said control knobwhereby said motor may be adjusted to any desired speed by operation ofsaid control knob.

3. In a speed control mechanism for phonographs, the combination of, amovable speedregulating member positioned in proximity to the drivingmeans of a phonograph and adapted to coact therewith, a manuallyoperable control member remotely positioned relative to saidspeed-regulating member, a Bowden-wire element extending between andconnected to said speed-regulating member and said control member sothat movement of said control member in one direction pulls directly onsaid BoWden-wire element to produce a corresponding movement of saidspeed-regulating member in one direction, biasing means for urging saidspeed-regulating member in the opposite direction, and means associatedwith said control member for holding it in any desired position inopposition to the pull, of said biasing means transmitted through saidBowden-wire element whereby the speed of said driving means may beadjusted through said speed-regulating member by movement of said manualcontrol member.

4. A speed-controlling device for phonographs, comprising, incombination, phonograph driving means, a supporting frame secured tosaid driving means, a speed-regulating member movably attached to saidframe and operatively connected to said driving means, resilient meansbiasing said member toward a predetermined position relative to saidframe, a control unit bracket adapted to be remotely positioned relativeto said driving means, a speed control lever movably attached to saidbracket, a Bowden-wire extending between said frame and said bracket,one element of said Bowden-wire being anchored at one end to said frameand at the other end to said bracket, one end of the other element ofsaid Bowden-wire being secured to said speed control lever and the otherend being secured to said speed-regulating member to pull against theforce of said resilient means when said speed control lever is moved inone direction, means for holding said latter lever in any desiredposition against the action of said resilient means thereby to positionsaid speed-regulating member in any desired position, and meansassociated with one end of one element of said Bowden-wire for adjustingits position with respect to its anchorage to vary the limits of therange of control of said speed control mechanism.

5. A speed-controlling device for phonographs, comprising, incombination, phonograph driving means, a supporting frame secured tosaid driving means, a speed-regulating member movably attached to saidframe and operatively connected to said driving means, a control unitbracket adapted to be remotely positioned relative to said drivingmeans, a speed control member movably attached to said bracket, aBowdenwire extending between said frame and said bracket. one element ofsaid Bowden-wire being anchored at one end to said frame and at theother end to said bracket, one end of the other element of saidBowden-wire being secured to said speed control member and the other endbeing secured to said speed-regulating member to position it as desired,and means associated with one end of one element of said Bowdenwire foradjusting its position with respect to its anchorage to vary the limitsof the range of control of said speed control mechanism.

6. A speed-controlling device for phonographs, comprising, incombination, phonograph driving means, a supporting plate secured tosaid driving means, a speed-regulating lever rotatably attached to saidplate and operatively connected to said driving means, a control unitbracket remotely positioned relatively to said driving means, a speedcontrol lever rotatably attached to said bracket, a Bowden-wire cableextending between said plate and said bracket, the sheath with saidspeed control lever for moving it' in one direction to pull on saidinner element of said Bowden-wire cable to move said speed-regulatinglever away from said; predetermined position, and means: for holdingsaid control lever in its adjusted position against the pull of saidspring whereby said speed-regulating lever may be rotated to any desiredposition by rotation of said. remotely positioned control lever.

JOSEPH M. LUCARELLE. CHARLES ECKLUND.

